- In the longest-ever retrospective study of 372 patients who underwent arthroscopic labral debridement, with or without chondroplasty, freedom from total hip arthroscopy (THA) was estimated to be 59% at 20 years
- Factors that contributed to the need for THA included age greater than or equal to 40 and chondral damage on both the femoral head and acetabulum, with damage on one surface being severe
- Regardless of patient age, the probability of needing THA was <10% in patients who had no chondral damage at the time of surgery
- For patients who presented with any degree of chondral damage on any surface, the risk of undergoing THA was twice as high for patients aged greater than or equal to 40 than for younger patients; risk increased as the severity and dispersion of damage increased, regardless of age
Many of the more recent arthroscopic treatments for intra-articular hip conditions focus on extending the life of the native joint. Examining long-term outcomes is essential to identifying the most effective treatments, especially since many patients are under 30 at the time of surgery.
A study published in Clinical Orthopaedics and Related Research was the first to gather outcomes data more than 10 years after arthroscopy. Maureen K. Dwyer, PhD, assistant research scientist in the Department of Orthopaedics at Massachusetts General Hospital, and colleagues report that the need for total hip arthroplasty (THA) within 20 years after arthroscopic labral debridement was associated with both patient age at the time of surgery and the presence and severity of chondral damage.
Need for THA
The researchers were able to contact 372 patients (384 hips) who underwent arthroscopic partial labral debridement at Mass General, with or without chondroplasty, between 1989 and 2000. The average age at the time of the procedure was 38 and the average time between arthroplasty and follow-up was 19 years.
At follow-up, 153 patients (41%) reported having needed THA on the same hip(s) that underwent arthroscopy. The average time to THA was seven years (range, 0–21 years), and 29% of hip repairs lasted at least 10 years before the patient required THA.
Based on Kaplan–Meier analysis, freedom from THA was estimated to be:
- 80% at five years
- 70% at 10 years
- 63% at 15 years
- 59% at 20 years
In multivariate regression analysis, factors that significantly affected the need for THA within 20 years were:
- Age ≥40 (two times greater risk of THA)
- Severe femoral head damage plus any degree of acetabular damage noted at the time of arthroscopy (five times greater risk)
- Severe acetabular damage plus any degree of femoral head damage (3.7 times higher risk)
- Absence of any chondral damage (90% lower risk)
The researchers find it interesting that severe damage isolated to either the acetabulum or femoral head at the time of arthroscopy was not associated with a later need for THA. In fact, such damage was more prevalent in the non-THA group. What mattered most to the life of the joint was the distribution of damage throughout the articular cartilage surfaces.
Probability of THA
A risk assessment based on the regression model revealed the probabilities of needing THA within 20 years of arthroscopic treatment of labral injuries:
- 2% for patients <40 years old at the time of surgery, with no chondral damage
- 7% for patients ≥40 years old at the time of surgery, with no chondral damage
- 38% for patients <40 years with any degree of chondral damage
- 66% for patients ≥40 years with any degree of chondral damage
The greater the degree of chondral damage, the greater the risk of THA.
The researchers conclude that patients who have arthroscopic treatment of labrochondral injuries before developing widespread chondral damage may be at reduced risk of needing THA within 20 years.
They suggest post-arthroscopy patient counseling about the long-term risk of THA, based on the current health of articular cartilage, so patients will have realistic expectations.
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